Liquid crystal display is generally formed by assembling a liquid crystal display panel and a backlight. The backlight mainly comprises a light source (such as, a lamp group), a backboard, a reflection plate, a frame, a light guide plate, a diffusion film, a lower prism film, an upper prism film, a polarizing sheet and the like. The upper prism film and the lower prism film are used for adjusting the direction of the light emitted from the diffusion film so that the light are converged and emitted along the front-view direction, and thereby the brightness is increased.
FIG. 1 is a structure of a conventional prism film. As can be seen from FIG. 1, the conventional prism film has a wavy structure. The wavy structure is easily scratched, so it is likely to generate white spots and/or bright spots thereon. Moreover, the conventional prism film is easy to generate a Moire phenomenon as shown in FIG. 2 (the Moire phenomenon refers to the phenomenon that the defect of bright and dark strips is generated due to the interference between the upper prism film and the lower prism film), and accordingly a decline in image quality of the display is resulted.